A155419 Number of ways to place zero or more nonadjacent 0,0 1,0 2,1 3,1 4,1 5,1 6,2 7,2 polyhexes in any orientation on a planar nXnXn triangular grid.

1, 7, 19, 52, 207, 826, 3466, 17019, 96663, 608856, 4591353, 39344454

Offset

7,2

Links

Table of n, a(n) for n=7..18.

Example

Maximal 11 X 11 X 11 example
.............1
............1.0
...........0.1.0
..........0.1.0.1
.........0.1.0.0.1
........0.1.0.0.1.0
.......0.0.1.0.0.1.0
......0.0.1.0.0.0.1.0
.....0.0.0.0.1.1.0.1.0
....0.1.1.1.1.0.0.1.0.0
...1.1.0.0.0.0.0.0.1.0.0

Crossrefs

Sequence in context: A155385 A155345 A155309 * A155246 A155414 A155374

Adjacent sequences: A155416 A155417 A155418 * A155420 A155421 A155422

Keyword

nonn

Author

R. H. Hardin Jan 22 2009

Status

approved